AxGen Structured Generation For Rust

This skill helps an agent write Rust code with the generated Ax package axllm. Use the generated package API, examples, and manifests; do not import TypeScript-only APIs unless you are editing the TypeScript package.

When To Use

• Build a structured generation program from a signature.
• Attach typed tools or MCP-derived tools to a generation call.
• Generate multiple validated structured samples and select a winner with a native callback.
• Use package examples for no-key scripted clients and provider-api calls.

Package Facts

• Language: Rust.
• Package: axllm.
• Package API docs: API.md and axir-api.json.
• Capability manifest: axir-capabilities.json.
• Runnable examples: examples/.
• Real network support: yes.
• Scripted no-key transport support: yes.
• Runtime profiles: javascript-quickjs.

Core Pattern

let program = axllm::ax("question:string -> answer:string")?;
let out = program.forward(&llm, inputs, None)?;

Provider Forward Options

AxGen merges constructor and per-call forward options before invoking the provider. Provider-facing keys such as promptCacheKey, sessionId, and contextCache therefore reach the chat request without being copied into program inputs. Per-call values override constructor defaults.

structuredOutputMode / structured_output_mode accepts auto, native, function, or json_object. Auto follows the selected profile/model ordering, with the provider-neutral singleton string/code JSON-object optimization. Explicit modes must be advertised and fail before transport otherwise. JSON-object mode retains exact-shape prompting, strict parsing, and one bounded correction retry without a synthetic __axOutput tool.

Multi-Sampling

• Set sampleCount / sample_count to request N provider candidates. Core parses and validates every candidate, preserving each provider result index.
• Without a result picker, AxGen returns candidate 0. A result picker receives all { index, sample } structured candidates and returns the winning list index; Core rejects an index outside 0..N-1.
• Native callback surface: with_sample_count / with_result_picker with AxResultPickerSample.
• OpenAI-compatible Chat and Gemini map multi-sampling to n and candidateCount. Anthropic rejects n > 1 explicitly.

Relevant API Surface

• AxGen: ax, AxGen
• Tools: tool, Tool
• MCP: AxMCPClient, AxMCPStreamableHTTPTransport, AxMCPStdioTransport

Guardrails

• Start from package examples for exact native syntax before inventing a new call shape.
• Use provider-api examples only when the user explicitly has provider credentials available.
• Use no-key examples for deterministic local checks and provider request mapping.
• Treat AxIR as the source of generated package truth: if package docs disagree with source code, update the compiler and regenerate packages.
• Do not copy repo-maintainer skills from tools/*/skills/ into user packages.